In Phase 1 of the contract, the modulated cap thin p-clad (MCTC) design concept was utilized to fabricate antiguided array lasers and alpha DFB lasers. The lateral refractive index variation required in implementing the designs was achieved by precisely modulating the thickness of the GaAs cap layer using a novel pulsed anodization/etching technique. At ten times threshold, the central lobe in the lateral far field of the best antiguided array lasers contained about 60% of the beam power and had a divergence of about 1.6 degrees. Since the yield of such devices was only about 5%, the main effort in Phase 2 was to develop epitaxial design with wide process windows and large discrimination factors for the fundamental array mode. Alpha DFB laser design studies showed that it was important to have a high lateral coupling/stripe width product and low loss in order to achieve high power operation. Various designs were implemented in both Phases of the contract with little success. It was concluded that the MCTC design concept was not useful for fabricating alpha dfb lasers because the large refractive index changes required were inextricably tied to high mode losses.